J. Phys. III France
Volume 4, Numéro 12, December 1994
Page(s) 2593 - 2600
DOI: 10.1051/jp3:1994299
J. Phys. III France 4 (1994) 2593-2600

Active species in N2 flowing post-discharges

A. Ricard1 and A. R. de Souza2

1  LPGP, Bât. 212, CNRS, Université Paris-Sud, 91405 Orsay, France
2  Depto. de Fisica, UFSC, 88.000, Florianopolis, SC, Brazil

(Received 3 December 1993, revised 27 April 1994 and 20 July 1994, accepted 1 September 1994)

The afterglow in D.C. and H.F. N 2 flowing discharges has been analysed by emission spectroscopy. Production of excited species has been studied in conditions of late $\Delta t =(1 - 5) \times 10^{-1}$ s and early $\Delta t =(0.5 - 5) \times 10^{-2}$ s afterglows. The late afterglow is characterized by the N 2 1st positive emission with a strong enhancement of the N 2(B, v' = 11) level compared to the other N 2(B, v') levels which is a signature of N atom density. By NO titration, we have determined that N/N 2 dissociation degrees are respectively 4.1% and 2.7% in a 60 W H.F. and in a 50 mA D.C. post-discharge at 4.5 Torr. The early afterglow is characterized by a strong 1st positive emission which has been analysed from the N 2(A) + N 2(X, v>5) excitation transfer reaction. By introducing a little CH 2(10 -4-10 -3) or H 2(10 -2-10 -1) into the N 2 D.C. and H.F. postdischarges, N 2(A) quenching rates have been obtained indicating that the N 2(A) is only excited on the two first vibrational states in the early afterglows.

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